This is implementation of Attributes added in PHP 8.0. However documentation for this feature is rather bad, so I'd advice you to use sth likehttps://3v4l.org/ to determinate how this feature really works.

Implemented:

• argument-less attribute#[MyAttribute]
• attribute with arguments#[MyAttribute(true)]
• attribute with named arguments#[MyAttribute(name:'Bob')]
• namespaced attributes#[\Ye\Old\Attribute]
• multiple attributes#[A,B,C]
• multilined attributes

#[A,B(true)]

• anonymous class attributes (single-line only)new #[MyAttribute] class {}, also it's valid to writenew#[MyAttribute]class{}
• Attribute as class name, for use as argument#[Attribute(Attribute::TARGET_CLASS)]
• test spec

Scopes

• meta.attribute.php for whole#[....]
• support.attribute.php for attribute name, w/ namespace scopes like in classes
• support.attribute.builtin.php forAttribute and future builtins
• arguments are the same as in function call

Not implemented

• multilined attributes for anonymous classes - I'm not sure if I should implement this, since it would need some trickery to add with TM grammar (feedback is welcome)